During the period from May to October 1969, the authors carried out a series of tests with the aim to ascertain the present status of susceptibility of adult cockraoches to various insecticides. The tests on the susceptibility of cockroaches to dieldrin, D.D.V.P., Diazinon; Dibrom, Malathion and lindane were performed with the topical application and the residual film methods under the conditions of 26 degrees C and 80% of relative humidity. The insects tested were collected from Seoul City and were reared at the laboratory. Some of the important results so far obtained can be summarized as follows: The median lethal doses (LD(50)) of the five insecticides against female adult cockroaches were: 0.4 ug/roach or 4.02 ug/body weight (gm) by Dieldrin, 0.29/roach or 2.88 ug/body weight (gm) by D.D.V.P., 0.29 ug/roach or 2.96 ug/body weight (gm) by Diazinon, 0.54 ug/roach or 5.37 ug/body weight (gm) by Dibrom, and 2.96 ug/roach or 29.60 ug/body weight (gm) by Malathion. And those against male adult cockroaches were: 0.18 ug/roach or 3.29 ug/body weight (gm) by Dieldrin, 0.27 ug/roach or 4.89 ug/body weight (gm) by D.D.V.P., 0.16 ug/roach or 2.91 ug/body weight (gm) by Diazinon, 0.49 ug/roach or 8.97 ug/body weight (gm) by Dibrom, and 1.32 ug/roach or 24.19 ug/body weight (gm) by Malathion. The level of susceptibility of adult cockroaches to the insecticides tested was 1.0-1.6 times higher as compared with the results obtained on the Japanese Takashi strain. The median knockdown times (LT(50)) of the female adult cockroaches by insectcides at 1% concentration of 3 mg per square centimetre were 1.82 hours by Malathion, 1.36 hours by Diazinon, 0.56 hours by Lindane, 0.50 hours by Dibrom, and 2.56 hours by D.D.V.P. A marked difference was seen to exist between the males and the females. The female cockroaches were more resistant than the male to Dieldrin, Diazinon and Malathion.
parasitology-arthropoda-cockcroach-Blattella germanica ; chemotherapy ; Dieldrin ; D.D.V.P. ; Diazinon ; Dibrom ; Malathion ; lindane ; resistance

This study was carried out to obtain the basic data for the preverition of chronic poisoning by organic phosphate pesticides. 6 sprayers who participated in the summer pest control programs of Jeonju city were chosen as the subjects in this study. Pesticides which were spread in the period of study are DDVP (1.09%), dursban (1.8%) and dibrom (1.9%). And from May 16, 1983 to Aug. 22, 1983, plasma cholinesterase activity, hematological and biochemical parameters were measured with several physical examinations for each sprayers and controls. Majors findings are as following; 1. Before pesticides were sprayed, plasma cholinesterase were 7.32+/-6 microM/20microliter/hr. in sprayers and 7.13+/-1.39 microM/20 microliter/hr. in the control group(p>0.05). 2. At 60th day of spraying, plasma cholinesterase activity of sprayers was 6.78+/-2.01 microM/20 microliter/hr. Which is significantly decreased from the pre-exposed value(p<0.01), but plasma cholinesterase activity in the control group was not changed. 3. The specific findings which suggested to organophosphorous poisoning were not found through the period of study. 4. Hematological and bichemical parameters were not significantly changed in the both groups.
Chlorpyrifos ; Cholinesterases* ; Dichlorvos ; Jeollabuk-do ; Naled ; Occupations* ; Pest Control ; Pesticides* ; Physical Examination ; Plasma* ; Poisoning